Tire



March 13, 1928.

L. A. BROWN TIRE I 2 Sheets-Sheet 1 Filed May 14, 1924 mnf R1/mol.- ZJZ. Erba/V31, /l @WwW/gee' n L. A. BROWN March 13, 1928.

A TIRE Filed May 14, 1924 2 Sheets-Sheet 2 Y @Vani-0f f ZZ gdm Brow/UiPatented Mar. 13, 1928.

UNIT-151D STATES A 1,662,599 PATENT' OFFICE.

LZ ADAM BROWN, OF ALTO, MICHIGAN, ASSIGNOR TO CORDUROY TIRE COMPANY, OFGRAND RAPIDS, MICHIGAN, A CORPORATION OF DELAWARE.

TIRE.

Application led May 14, 1924. Serial- No. 718,243.

The present invention relates to tires, and more particularly to balloontires for automobiles and the like; and its ob'ect is, generally, toprovide a tire improve in certaln respects hereinafter appearing; and,more particularly, to provide such a tire having spacedcircumferentially-extending reslhent ribs with cross-memberstherebetween so disposed as to cause such'portions ofthe r1bswhichcontact the road surface to assume a non-parallel interrelation andthus au ment the tractive efficiency of the tire; an further, to providesuch a tire having a fiexible body and like `ribs extending outwardlytherefrom, the body being thus sufficiently fiexible to cause the ribsin the flexed area of the tire to approach eachother by such flexingresulting from thrusts from wlthout.

This and any other objects hereinafter appearing are attained by, andthe invention finds preferable embodiment in, the tire structurehereinafter particularly described in the body of this specification andillustrated by the accompanying drawings, in which Figure 1 is a sideview of a portion of a tire; v

Figure 2 is a cross-sectional view thereof taken on line 2 2 of Figurel;

Figure 3 is a cross sectional view of a portion of the tire showing thesame fiexed inwirdly by contact with a projection in the roa l Figure 4is a similar cross-sectional View of the tire thus flexed in anotherplace Figure 5 is a view of the tread portion of the tire, developed; nFigure 6 is a like view of the same, showing t e ribs thereof inositionsj into which they have beeny flexed by contact with the road;

tion of a. tire, showing a modified construction thereof; and l l Figure8 is a like View of the same in contact with the road.

The tire shown in the drawings is the casin portion of a pneumatic tirefor automoblles. This tire has a flexible body 1, comprising a fabricinner part 2 and a rubber outer part 3. The tire has also a plurality ofspaced resilient ribs 4 (integral with the rubber part 3) extendingcircumferentially of the tire and outwardly from its body 1,. i. e.outwardly from the dottedline 5 appearing on the cross-sectional views.This body 1 is1 sufficiently fiexible that it may be flexed inwardly bysuch thrusts from without as may be caused by the tire-in theautomobiles travel-striking; a projection 6 in the road, as illustratedin Figures 3 and 4. This inward fiexing of the body 1 causes the ribs inthe tires fiexed area to approach each other and assume the positions ofthe ribs 41 in Figures 3 and 4. By this approaching movement, adjacentribs in the flexed area are brought so near each other (or into contactwith each other) that the force of the inward thrust is particularlywell cushioned and the tire is enabled to better resist the same and toresist injury therefrom.

When however the body 1 of the tire returns to normal shape, or isflexed oppositely, t-he ribs-as the ribs 42-recede from each other, asshown in said Iviews. The result of this formation of thetire with abody 1 sufficiently flexible for said purpose, and with the spacedcircumferential ribs 4,

- is thus to make possible a tire having a minimum amount of rubbertread and yet a suicient capability of resisting the jars and joltsresulting from encountering projections in the road, and .a greatercapability of resisting wear and tear.

As shown, the tire has spaced apart resilient cross members 7 betweenadjacent ribs 4, the cross members on one side of each rib being inystaggered relation to the cross members on the opposite side thereof, aspar- 'ticularlyshown in Figures 5 and 6. The

normal interrelative position of the ribs and cross members is seen inFigure 5; but said v parts, when in contact with the road surface,assume (by the weight of the load carried n o thereby) the interrelativepositions seen in Figure 7 1s a cross-sectional view of a porparallelribs 4 not only at the sides of the Y tread portion of the tire, butalso throughoutthe tread portion as well, peculiarly Well adapts thetire shown in the views to the flexing operation and el'ect thereofabove set. forth; moreover7 there is no such distortion in a tire havingsuch a ribbed forniation as exists in tires having such ribs broken intoparts by intervening recesses and the like.

In Figures 7 and S is shown a modified form of the tire. In these views,the ribs (as in other views) are in eross-section approximately segmentsof circles. The middle rib 43 is of greater cross-sectional dimensionsthan the others, and at each side thereof are a pair of ribs 44. 44 ofless cross-section dimensions than the middle rib. All these ribs 4* areapproximately of the same cross-sectional dimensions. Normally thesefive ribs 43 and 4* are the ones which Contact the road, as seen inFigure 8. As such ribs are squeezed or pressed toward each other in thelower part of the tire in Contact with the road, and recede from eachother as the wheel rolls tocarry them out of contact with the road,these ribs are somewhat Worn and abraded by their sidewise slippingmovement on the road. I have found that such sidewise slipping movementis lessened by formingr the pairs 4* of approximately equalcross-sectional dimensions, as shown in Figures 7 and 8.

I claim:

In a low pressure tire havingr a carcass ot' ereater flexibility thanthe carcass of a high pressure tire for the same load and adapted tocarry a predetermined load at an inflation pressure substantiallyreduced below that o't a high pressure tire for the same load, said tirebeing substantially increased in cross sectional area and decreased inratio of' Wall thickness to cross sectional area with respect to a highpressure tire for the same load, the combination of a relatively thicktread sub-divided by grooves proportioned with respect to the increasedflexibility of the carcass and the thickness of the tread to be closedby the greater flexing of the carcass under normal loading to present asubstantially solid tread surface to th road under normal load andwithout detrimental friction to the carcass.

In testimony whereof I have hereunto set my hand at Grand Rapids,Michigan, this 10th day of May, 1924.

LZ ADAM BROWN.

